The disclosure relates to a carriage apparatus for carrying a tool string down a wellbore in a wireline logging, and an orientation apparatus and hole finder device for a wireline logging tool string. In some embodiments the carriage includes a protection structure which extends longitudinally around a wheel of the apparatus to thereby prevent a side of the wheel from contacting a wall of the wellbore. In some embodiments an orientation apparatus and hole finder are arranged so that the orientation apparatus orientates the hole finder device in the wellbore so that a tip of a nose section of the hole finder is elevated above a low side of the wellbore by a height and offset from and above a longitudinal axis of the tool string.

The disclosure relates to a sensor transportation apparatus to convey an elongate sensor assembly through a wellbore. The sensor transportation apparatus comprises at least one engagement structure to connect the sensor transportation apparatus to the sensor assembly, and a pair of wheels arranged to rotate about an axis of rotation substantially perpendicular to a longitudinal axis of the sensor assembly when the transportation apparatus is connected to the sensor assembly, and an orientation structure comprising at least one orientation projection, in a transverse outline of the sensor transportation apparatus a said orientation projection extending between the pair of wheels so that the shortest distance between a centre of mass of the elongate sensor assembly and the wellbore wall is when the pair of wheels are in contact with the wellbore wall.

The disclosure relates to a sensor transportation apparatus to convey an elongate sensor assembly through a wellbore. The sensor transportation apparatus comprises at least one engagement structure to connect the sensor transportation apparatus to the sensor assembly, and a pair of wheels arranged to rotate about an axis of rotation substantially perpendicular to a longitudinal axis of the sensor assembly when the transportation apparatus is connected to the sensor assembly, and an orientation structure comprising at least one orientation projection, in a transverse outline of the sensor transportation apparatus a said orientation projection extending between the pair of wheels so that the shortest distance between a centre of mass of the elongate sensor assembly and the wellbore wall is when the pair of wheels are in contact with the wellbore wall.

A logging tool assembly comprises an elongate sensor assembly, a plurality of sensor transportation apparatuses for transporting the elongate sensor assembly through a wellbore, and an orientation structure. The sensor transportation apparatuses are spaced apart along the elongate sensor assembly. Each sensor transportation apparatus comprises an engagement structure to connect the sensor transportation apparatus to the elongate sensor assembly and prevent relative rotation between the sensor transportation apparatus and the elongate sensor assembly, and one or more pairs of wheels arranged to rotate on an axis of rotation substantially perpendicular to a longitudinal axis of the elongate sensor assembly. The axes of rotation of the pairs of wheels of said transportation apparatuses are parallel. The orientation structure is connected to the elongate sensor assembly to prevent relative rotation between the orientation structure and the elongate sensor assembly. The orientation structure comprises at least one radially extending orientation projection. In a transverse outline of the logging tool assembly a said orientation projection extends between the pair of wheels so that the shortest distance between a centre of gravity of the elongate sensor assembly and the wellbore wall is when the pair of wheels of the transportation apparatus is in contact with the wellbore wall.

A logging tool assembly comprises an elongate sensor assembly, a plurality of sensor transportation apparatuses for transporting the elongate sensor assembly through a wellbore, and an orientation structure. The sensor transportation apparatuses are spaced apart along the elongate sensor assembly. Each sensor transportation apparatus comprises an engagement structure to connect the sensor transportation apparatus to the elongate sensor assembly and prevent relative rotation between the sensor transportation apparatus and the elongate sensor assembly, and one or more pairs of wheels arranged to rotate on an axis of rotation substantially perpendicular to a longitudinal axis of the elongate sensor assembly. The axes of rotation of the pairs of wheels of said transportation apparatuses are parallel. The orientation structure is connected to the elongate sensor assembly to prevent relative rotation between the orientation structure and the elongate sensor assembly. The orientation structure comprises at least one radially extending orientation projection. In a transverse outline of the logging tool assembly a said orientation projection extends between the pair of wheels so that the shortest distance between a centre of gravity of the elongate sensor assembly and the wellbore wall is when the pair of wheels of the transportation apparatus is in contact with the wellbore wall.

Aspects of the disclosure are directed to a system comprising: a tank that stores a fluid, and a conduit that includes a first end and a second end, where the conduit is configured to convey at least a portion of the fluid stored in the tank from the second end of the conduit to the first end of the conduit, where a first end region of the conduit coinciding with the second end of the conduit has a first end region density and the fluid has a fluid density, where the first end region density is greater than or equal to the fluid density such that the first end region of the conduit remains immersed in the fluid stored in the tank when the fluid in the tank is under negative gravity conditions.

Aspects of the disclosure are directed to a system comprising: a tank that stores a fluid, and a conduit that includes a first end and a second end, where the conduit is configured to convey at least a portion of the fluid stored in the tank from the second end of the conduit to the first end of the conduit, where a first end region of the conduit coinciding with the second end of the conduit has a first end region density and the fluid has a fluid density, where the first end region density is greater than or equal to the fluid density such that the first end region of the conduit remains immersed in the fluid stored in the tank when the fluid in the tank is under negative gravity conditions.

A high-pressure grease block including a grease block body having a grease block cavity defined therein and adapted to cooperate with a valve body. A first port is adapted for sealing connection to a port on the valve body such that a valve grease cavity defined within the valve body communicates with the grease block cavity. A second port communicates with the grease block cavity and is adapted for receiving a greasing assembly and a third port communicates with the grease block cavity and is adapted for receiving a bleeding assembly.

A high-pressure grease block including a grease block body having a grease block cavity defined therein and adapted to cooperate with a valve body. A first port is adapted for sealing connection to a port on the valve body such that a valve grease cavity defined within the valve body communicates with the grease block cavity. A second port communicates with the grease block cavity and is adapted for receiving a greasing assembly and a third port communicates with the grease block cavity and is adapted for receiving a bleeding assembly.

A sensor transportation apparatus to convey an elongate sensor assembly through a wellbore, the sensor transportation apparatus comprises a pair of axles and a pair of wheels corresponding with the pair of axles with each wheel mounted on a respective said axle to rotate about an axis of rotation perpendicular to a longitudinal axis of the elongate sensor assembly. A protection structure extends longitudinally around each wheel to prevent a side of the wheel from contacting a wall of the wellbore. Each wheel extends above and below the protection structure to contact a side of the wellbore.